" - - American officials lied to British ministers over
the use of "internationally reviled" napalm-type firebombs in Iraq.

Yesterday's disclosure led to calls by MPs for a full statement to the Commons
and opened ministers to allegations that they held back the facts until after
the general election.

Despite persistent rumours of injuries among Iraqis consistent with the use of
incendiary weapons such as napalm, Adam Ingram, the Defence minister, assured
Labour MPs in January that US forces had not used a new generation of incendiary
weapons, codenamed MK77, in Iraq.

But Mr Ingram admitted to the Labour MP Harry Cohen in a private letter obtained
by The Independent that he had inadvertently misled Parliament because he had
been misinformed by the US. "The US confirmed to my officials that they had not
used MK77s in Iraq at any time and this was the basis of my response to you," he
told Mr Cohen. "I regret to say that I have since discovered that this is not
the case and must now correct the position."

Mr Ingram said 30 MK77 firebombs were used by the 1st Marine Expeditionary Force
in the invasion of Iraq between 31 March and 2 April 2003. They were used
against military targets "away from civilian targets", he said. This avoids
breaching the 1980 Convention on Certain Conventional Weapons (CCW), which
permits their use only against military targets.

Britain, which has no stockpiles of the weapons, ratified the convention, but
the US did not.

The confirmation that US officials misled British ministers led to new questions
last night about the value of the latest assurances by the US. Mr Cohen said
there were rumours that the firebombs were used in the US assault on the
insurgent stronghold in Fallujah last year, claims denied by the US. He is
tabling more questions seeking assurances that the weapons were not used against
civilians.

Mr Ingram did not explain why the US officials had misled him, but the US and
British governments were accused of a cover-up. The Iraq Analysis Group, which
campaigned against the war, said the US authorities only admitted the use of the
weapons after the evidence from reporters had become irrefutable.

Mike Lewis, a spokesman for the group, said: "The US has used internationally
reviled weapons that the UK refuses to use, and has then apparently lied to UK
officials, showing how little weight the UK carries in influencing American
policy."

He added: "Evidence that Mr Ingram had given false information to Parliament was
publicly available months ago. He has waited until after the election to admit
to it - a clear sign of the Government's embarrassment that they are doing
nothing to restrain their own coalition partner in Iraq."

The US State Department website admitted in the run-up to the election that US
forces had used MK77s in Iraq. Protests were made by MPs, but it was only this
week that Mr Ingram confirmed the reports were true.

Mike Moore, the Liberal Democrat defence spokes-man, said: "It is very serious
that this type of weapon was used in Iraq, but this shows the US has not been
completely open with the UK. We are supposed to have a special relationship.

"It has also taken two months for the minister to clear this up. This is welcome
candour, but it will raise fresh questions about how open the Government wished
to be... before the election."

The MK77 bombs, an evolution of the napalm used in Vietnam and Korea, carry
kerosene-based jet fuel and polystyrene so that, like napalm, the gel sticks to
structures and to its victims. The bombs lack stabilising fins, making them far
from precise.